Ölansaugsieb verstopft

The mesh screen on the oil pump's pickup in the sump, blocked so the pump cannot draw enough oil. It is the engine's equivalent of the fuel pump's strainer — the first filter in the system, never serviced, and reachable only by dropping the sump.

It starves the pump rather than the bearings, and that ordering explains the symptoms. The pump cavitates against the restriction, so pressure falls under demand while remaining plausible at idle when demand is lowest — the opposite of the pattern worn bearings produce, which is a genuinely useful distinction. Pressure that is fine at idle and falls at speed points at supply, not clearance.

What blocks it says something about the engine's history. Sludge from extended oil change intervals, or debris from a previous failure that was never cleaned out. Finding a blocked pickup is a reason to inspect the whole sump, because a new pump drawing through the same sludge blocks again — and the sludge itself indicates deposits elsewhere in the engine that a single oil change will not clear.